Ellie's scientist grandfather has discovered a way to reverse aging, and consequently has turned into a teenager--which makes for complicated relationships when he moves in with Ellie and her mother, his daughter.

When thirteen-year-old Ellie's Grandpa Melvin, a world-renowned scientist in the body of a fourteen-year-old boy, comes for an extended visit, he teaches her that experimenting--and failing--is part of life.--